Electric meter.



T. DUNCAN. ELECTRIC METER.

APPLICATION-FILED FEB. 26,1904.

PATENTED AUG. 1, 1905.

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UNITED STATES PATENT OFFICE,

ELECTRIC IVIET ER.

Specification of Letters Patent.

Patented Aug. 1, 1905.

Application filed February 26, 1904. Serial No. 196,469.

To all whom it may concern:

Be it known that I, THoMAs DUNCAN, a citizen of the United States,residing at Lafayette, in the county of Tippecanoe and State of Indiana,have invented a certain new and useful Improvement in Electric Meters,of which the following is a full, clear, concise, and exact description,reference being had to the accompanyingdrawings, forming a part of thisspecification.

My invention relates to electric meters, and has for its object theprovision of improved mechanism whereby the rotating elements of themeters may be accurately and effectively suspended magnetically, theinvention being of particular utility in connection with commutatedmotor integrating Wattmeters. Oommutated motor-wattmeters as at presentplaced upon the market each employ a revoluble member consisting ofa'spindle having a lower endthrust bearing and an upper side-thrustbearing and carrying the armature and dampingdisk. The end-thrustbearing at the bottom of the spindle is usually a sapphire jewel, whichbecomes easily broken or is roughened in a short time by the action ofthe spindlepoint. This roughening or wearing of the jewel-bearing andspindle-point is augmented to quite an extent by the entrance of dustwithin the meter, which settles upon the jewel and, mixing with the oilused in the jewel-cavity, forms a grinding mixture that frequentlyspeedily destroys the polished bearing-sur faces of both jewel andspindle-point. This roughening results, primarily, in causing the meterto be slow on some loads, and if permitted to continue thecharacteristic of the meter is lowered throughout itsentire range. Whenthis condition is present, it means that the central station may besupplying energy at a loss, in View of the fact that the major portionof the meters are usually in service on the low load end of theircharacteristics.

One feature of my invention resides in the provision of an end-thrustbearing for the upper end of the meter-shaft in combination with meansfor magnetically suspending the meter-shaft, said end-thrust bearingbeing so constructed as to limit the said shaft or spindle to a singleaxis of rotation, there being associated elsewhere with the meter-shaft,preferably at its lower end, a side-thrust bearing that cooperates withthe end-thrust bearing in confining the spindle to asingle axis ofrotation. One element of the magnetic suspension device is mountedexterior of the meterrotating member and is desirably in the form of apermanent magnet, a complemental member of the magnetic suspendingdevice being a body of magnetic material preferably fixedly secured uponthe meter-spindle, said body of magnetic material being preferably inthe form of a disk that is disposed in a plane at right angles to theaxis of rotation of the spindle, and therefore lying in the plane ofrotation of said spindle. The upper end-thrust bearing is madeadjustable with respect to the permanent magnet, so that the extent towhich the upper end of the shaft is moved against its end-thrust bearingmay be nicely determined, (sillich adjustment being longitudinal of thespin- Another feature of my invention resides in means whereby thesuspending-magnet is en abled not only to support the rotating elementof the meter, but also acts as a damping or retarding magnet, to whichend the shaft of the meter carries a damping-disk arranged within theinfluence of said magnet to secure a proper retardation in the speed ofthe meter. The disk of magnetic material and the damping-disk arepreferably assembled into a composite disk, both being subject to thesame flux from the suspending-magnet, the

retarding-disk being desirably interposed between the suspending-magnetand the damping-disk to secure the best effect upon said damping-disk. r

I will explain my invention more fully by reference to the accompanyingdrawing, illustrating certain structural features thereof anddiagrammaticallythe connections thereof.

In the drawing there is shown any suitable source of current a thatsupplies the mains I) b, that extend to a district of consumption atwhich I have indicated lamp 0. The current or field-winding of the meteris subdivided into coils d d, included in one of the mains I). Thepressure-winding of the meter, the meter illustrated being a commutatedmotor integrating wattmeter, is subdivided into coils constituting anarmature f, which armature is provided with a commutator whose segments9 engage the commutator brushes h h. The commutator and armature Thearmature has desirably included in circuit therewith a torque orcompensating coil Z, provided for the purpose of overcoming initialfriction, there being also desirably a resistance m in thearmature-bridge for adapting the meter to a selected voltage. The lowerend of the shaft instead of being provided with an endthrust bearing ashitherto is provided with a side-thrust bearing 01, that serves toengage the side of the spindle or a reduced portion thereof to preventmaterial lateral deflection of this part of the spindle. The upperendthrust bearing 0 is provided with a flaring recess p, narrowingtoward the top and flaring toward the bottom, so that the upper end ofthe spindle will readily be guided into place and practically limited toa single axis of rotation. At the upper end of the conical recess in thebearing 0 is a jewel-block 7, with which I desirably engage a hard-steelball r, that in turn is engaged by the upper end of the spindle. Thebearing 0, it will be apparent, is in the form of an inverted cupobstructing the passage of dust and preventing its lodgment upon thejewel-block. The engagement between the meter-spindle(which may beconsidered as including as one of its sections the hard-metal ball 7.))and the upper endthrust bearing is desirably effected bystationarily-mounted permanent magnet s, preferably of horseshoe form,within whose field is arranged a disk 2? of magnetic material.preferably of iron. In order that the degree of pressure of the upperend of the shaft against its end-thrust bearing may be nicely regulatedwith respect to the flux and the weight of the rotating elementsupported thereby,1 provide means whereby the said upper thrust-bearingmay be adjusted axially or lengthwise of the spindle and with referenceto the supporting-magnet. To this end the upper bearing is desirablymounted upon a brace 10, which may for convenience be attached to thepermanent magnet and which at its central portion has engagement with athreaded bolt o, with which the bearing 0 desirably has separable andthreaded engagement. A vertical adjustment of the bolt 1: may be had byturning it within the supporting-brace a, which adjustment after being.secured may be maintained by a set-nut w.

The same magnet that effects the magnetic suspension of the shaft 1'with the commutator and armature also desirably effects a retardinginfluence, for which purpose a damp ing-disk a: of non-magnetic metal,as aluminium, is mounted upon the spindle. in order that the samedamping-magnet may most effectively operate upon the damping-disk and atthe same time support or suspend the rotatmg element, said disltst and ware compounded or formed into one mechanical struc- .way in which thecompound disk is made up,

as other means may be devised for making the compound disk of magneticand non-magnetic metals for the purposes set forth. By means of theadjustable upper end-thrust bearing the ball 1' may be made to pressjust slightly against the jewel q, thereby greatly reducing the wear ofthe parts. In the preferred embodiment of the invention the ball aismagnetized and in that way held in place as a part of the meter-spindle.

It is obvious that changes may be made in the construction shown withoutdeparting from the spirit of my invention, and I. do not, therefore,wish to be limited to the precise mechanism illustrated; but,

Having thus described my invention, [claim as new and desire to secureby Letters Patent 1. The combination with a motor-wattmeter whose shafthas a lower bearing, and an upper inverted en d-thrust bearing, of amagnetic suspension device for supporting the rotating ele ment of themeter, and mechanism for effecting adjustment of the end-thrust bearingaxially of the shaft, the bearing at the upper end of the shaft servingto aline the shaft at the upper end and to prevent lateral deflectionthereof mechanically, substantially as dcscribed.

52. The combination with a motor-wattmeter whose shaft has a lowers'ide-tl1r1.1 st bearing, and an upper inverted end-thrust bearing, of amagnetic suspension device for supporting the rotating element of themeter, and mechanism for effecting adjustment of the end thrust bearingaxially of the shaft, the hearing at the upper end of the shaft servingto aline the shaft at the upper end and to prevent lateral deflectionthereof mechanically, substantially as described.

3. The combination with a motor-wattmeter whose shaft has a lower bearing, and an upper inverted end-thrust bearing substantially confiningthe upper end of the IT16t8F-SlliLfil to a single axis of rotation, of amagnetic suspension device for supporting the rotating element of themeter, and mechanism for effecting adjustment of the end-thrust bearingaxially of the shaft, the bearing at the upper end of the shaft servingto aline the shaft at the upper end and to prevent lateral (.lefilectionthereof mechanically, substantially as described.

L. The combination with a motorwattmeter whose shaft has a lowerside-thrust bearing, and an upper inverted end-thrust ljiearing,substantially confining the upper end of the meter-shaft to a singleaxis of rotation, of a magnetic suspension device for supporting theretating element of the meter, and mechanism for effecting adjustment ofthe emf-thrust bear ing axially of the shaft, the bearingat the upperend of the shaft serving to aline the shaft at the upper end and toprevent lateral defleetion thereof mechanically, substantially asdescribed.

' '5. The combination with amotor-wattmeter whose shaft has a lowerbearing, and an upper inverted end thrust bearing, of a magneticsuspension device for supporting the rotating element of the meter, andmechanism for effecting adjustment of the end-thrust bearing axially ofthe sh aft, said bearings substantially confining the shaft to a singleaxis of rotation, the bearing at the upper end of the shaft serving toaline the shaft at the upper end and to prevent lateral deflectionthereof mechanically, substantially as described.

6. The combination with a motor-wattmeter -whose shaft has alowerside-thrust bearing,

and an upper inverted end-thrust bearing, of a magnetic suspensiondevice for supporting the rotating element-of the meter, and mechanismfor effecting adjustment of the endthrust bearing axially of the shaft,said bearings substantially confining the shaft to a single axis ofrotation, the bearing at the upper end of the shaft serving to aline theshaft at the upper end and to prevent lateral defiection thereofmechanically, substantially as described.

7. The combination with a moto'r-wattmeter whose shaft has a lowerbearing, and an upper inverted end-thrust bearing, of a magneticsuspension device for supporting the rotating element of the meter andincluding a body of magnetic material moving with the shaft and astationarily-mounted magnet within whose field the said body of magneticmaterial is located, and mechanism for effecting adjustment of theend-thrust bearing axially of the shaft and with reference to saidmagnet, the bearing at the upper end of the shaft serving to aline theshaft at the upper end and to prevent lateral deflection thereofmechanically, substantially as described.

8. The combination with a motor-wattmeter whose shaft has a lowerside-thrust bearing, and an upper inverted end-thrust bearing, of amagnetic suspension device for supporting the rotating element of themeter and including a body of magnetic material moving with the shaftand a stationarily-mounted magnet within whose field the said body ofmagnetic material is located, and mechanism for effecting adjustment ofthe end-thrust bearing axi ally of the shaft and with reference to saidmagnet, the bearing at the upper end'of the' lateral deflection thereofmechanically, substantially as described.

10. The combination with a motor-wattmeter whose shaft has a lowerside-thrust bearing, and an upper inverted end-thrust bearing,

substantially confining the upper end of the meter-shaft to a singleaxis of rotation, of a magnetic suspension device for supporting therotating element of the meter and including a body of magnetic materialmoving with the shaft and a stationarily-mounted magnet within whosefield the said body of magnetic material is located, and mechanism foreffecting adjustment of the end-thrust bearing axially of the shaft andwith reference to said magnet, the bearing at the upper end of the shaftserving toaline the shaft at the upper end and to prevent lateraldeflection thereof mechanically, substantially as described.

11. The combination with a motor-wattmeter whose shaft has a lowerbearing, and an upper inverted end-thrust bearing, of a magneticsuspension device for supporting the rotating element of the meter andincluding a body of magnetic material moving with the shaft and astationarily-mounted magnet within whose field the said body of magneticmaterial is located, and mechanism for efiecting adjustment of theend-thrust bearing axially of the shaft and with reference to saidmagnet, said bearings substantially confining the shaft to a single axisof rotation, the hearing at the upper end of the shaft serving to alinethe shaft at the upper end and to prevent lateral deflection thereofmechanically, substantially as described 12. The combination with amotor-wattmeter whose shaft has alower side-thrust bearing, and an upperinverted end-thrust bearing, of a magnetic suspension device for sup-.

porting the rotatingelement of the meter and including a body ofmagnetic material moving with the shaft and a stationarily-mountedmagnet within whose field the said body of magnetic material is located,and mechanism for effecting adjustment of the end-thrust bearing axiallyof the shaft and with reference to said magnet, said bearingssubstantially confining the shaft to a single axis of rotation, thebearing at the upper end of the shaft serving to aline the shaft at theupper end and to prevent lateral deflection thereof mechanically,substantially as described.

13. The combination with a motor-wattmeter whose shaft has a lowerbearing and an upper inverted end-thrust bearing, of a magnetic deviceincluding a stationarily-mounted magnet and a body of magnetic materialmoving with the rotating element of the meter and arranged within thefield of said magnet,

said end-thrust bearing being constructed to confine the upper end ofthe shaft to a substantially fixed axis of rotation, the hearing at theupper end of the shaft serving to aline theshaft at the upper end and toprevent lateral deflection thereof mechanically, substantially asdescribed.

14. The combination with a motor-wattmeter whose shaft has a lowerside-thrust bearing and an upper inverted end-thrust bearing, of amagnetic device including a stationarily-mounted magnet and a body ofmagnetic material moving with the rotating element of the meter andarranged within the field of said magnet, said bearings serving toconfine the shaft to a substantially fixed axis of rotation, the hearingat the upper end of the shaft serving to aline the shaft at the upperend and to prevent lateral deflection thereof mechanically,substantially as described.

15. The combination with a motor-wattmeter whose shaft has a lowerbearing and an upper inverted end-thrust bearing, of a magnetic deviceincluding a stationarily-mounted magnet and a body of magnetic materialmoving with the rotating element of the meter and arranged within thefield of said magnet, said bearings serving to confine the shaft to asubstantially fixed axis of rotation, the bear ing at'the upper end ofthe shaft serving to aline the shaft at the upper end and to preventlateral deflection thereof mechanically, substantially as described.

16. The combination with a motor-wattmeter, of a stationarily -mountedsuspending magnet and a disk of magnetic material upor the shaft andwithin the field of said magnel to support the rotating element of themeter. and a damping or retarding disk also subjec to the influence ofsaid magnet that thus acts also as a clamping-magnet, said disks beingassembled into a compound disk, the hearing at the upper end of theshaft serving to alini the shaft at the upper end and to prevent lateral deflection thereof mechanically, substan tially as described.

17 The combination with a motor-wattme ter, of a stationarily mountedsuspendim magnet, and a compound disk of magnetic ant non-magnetic metalupon the shaft and with in the field of said magnet to support and retard the rotating element of the meter, tlr bearing at theupper end ofthe shaft servin; to aline the shaft at the upper end and to pre ventlateral deflection thereof mechanically substantially as described.

In witness whereof I hereunto subscribe m name this 20th day ofvFebruary, A. D. 1904 THOMAS DUNCAN.

Witnesses:

EUGENE I'IALFORD OoRsELLIs, ROYAL A. STREETER.

